Hypodermic unit and method of making same



Jan. 10, 1950 I w. ERHARD 2,494,290

HYPODERMIC UNIT AND METHOD OF MAKING SAME Filed June 5, 1944 @witk v INVENTOR.

M ZIP/ 412p BY Patented Jan. 10, 1950 HYPODERMIC UNIT AND METHOD OF MAKING SAME William Erhard, North Bergen, N. J assignor to E. R. Squibb & Sons, New-York, N. ;Y., a corporation of New York a Application June 3, 1944,-"S erial No. 538,660

This invention relates to articles commonly known as hypodermic units, enabling medicines and other substances to be promptly and efficiently administered by injection directly from sterile original packages; and it relates particularly to hypodermic units of the type shown and described in United States Patent No. 2,219,301, comprising a hermetically-sealed collapsible softmetal tube having an integrally-extruded, readily-' pierceable, blind discharge end, a hypodermic needle immovably secured to the tube, with the lumen of the needle communicating with the outside of the blind end, and a stifi wire longer than and carried in the lumen of the needle, for piercing the blind end. a

In the commercial production of these units prior to this invention, the collapsible soft-metal tube was formed with an externally-tapered neck terminating in the integrally-extruded, readilypierceable blind end, the hypodermic needle was rigidly secured to a. hub having a corresponding internal taper; and the needle was secured to the tube by positioning the needle hub over the tube neck and forcing it into frictional engagement therewith. Occasionally, in the production of such units on a large scale, defective units were obtained, with the needle hub so insecurely attached to the tube neck that these parts became disengaged on manipulation of the unitespecially when removing a tightly-fitting protective cover (the cover enclosing the needle and wire and detachably secured to the needle hub). Io assure absence of such defect (which would, of course, nullify the manifestly vital dependabilityin-use characteristic of these units), the completed units had to be tested to determine whether the attachment of the needle hub to the tube neck was sufliciently secure. The defect was found to arise principally from the variations in the internal taper of the needle hubs, it being difl'icult to keep within the necessarily narrow tolerance in the machining of these hubs.

It is the object of this invention to provide an advantages method of producing hypodermic units, and improved collapsible tubes for the production of hypodermic units.

The improved collapsible tubes of this invention are characterized by an externally-tapered neck terminating in an intergrally-extruded readily-pierceable blind end having a substantially-overall concavity (hereinafter referred to as a dished blind end); and the advantageous method of this invention essentially comprises extruding such improved collapsible tube, positioning the hub of a hypodermic needle over the tube neck, the hub having a corresponding in-- ternal taper terminating in a substantially-flat inside face at a depth less than the height of the tube neck, and forcing the needle hub upon the tube neck until the rim of the dished blind end is deformed by the inside face of the hub. (The term taper is employed herein in its conven-' tional sense as designating a regular or gradual narrowing toward one end, and hence excluding a threaded neck, for example.)

By the use of this invention, a tight fit of the needle hub at both ends of the tube neck is assured; because the lower end of the hub wall always fits tightly somewhere near the base of the tube neck, and as the needle hub is forced 1 down further on the neck, its inside face is" pressed againstthe rim of the dished blind end and causes the metal of the rim to be transported outwardly against the upper end of the hub wall, providing a tight lit in this zone also.

The invention will be described in detail inconnection with the accompanying drawing,

wherein: I v

Fig-.1 is an enlarged fragmentary axial section of the improved collapsible tube of this inven- ,.tion, various dimensions (e. g., the taper of the neck) being exaggerated for purposes 'of clear" illustration;

Fig. 2 is an enlarged fragmentary axial sec-' tion of the collapsible tube shown in Fig. l as-'- sembled with the needle hub, and illustrating the mode of assembly, various dimensions again being tube having a cylindrical wall I, a conventionally-shaped shoulder 2, and an externally-tapered neck 3 terminating in a readily pierceable Y blind end 4, which is dished, the rim 5 constituting in effect an extension of the tapered neck beyond the plane of the central portion of the blind end.

In the alternative form shown in Fig. 3, the dished blind end 6 has a fiat central portion, and the rim 1 constitutes in effect an extension of the tapered neck 3 beyond this central portion.

The collapsible tube shown in Fig. 1, for example, is assembled with the needle as follows: [As shown in Fig. 2, the needle is of the c0nventional type comprising a pointed cannula III (e. g., of stainless steel) rigidly secured to hug I l (e. g., of brass), the hub wall having a corresponding internal taper l2 terminating in a substantiallyfiat inside face I 3 at a depth less than the height of the tube neck] The open-ended tube is slipped over and held upright by an appropri ately-shaped supporting mandrel IS; the hub of the needle is positioned over the tube neck and then forced down to the position shown in Fig. 2 by means of a plate 16 having an aperture I! to accommodate the cannula l9. As the hub is forced down, the lower end of the hub wall will always fit tightly somewhere near the base of the neck. If the internal taper of the hub wall fully corresponds with that of the tube neck (and the parts are equidimensioned), there will then be a maximum area of intimate contact, with a consequent perfect frictional attachment. If the internal taper of the hub is such that the upper end of the tube neck seats at a distance from the inside face of the hub, the hub may be forced further on there is also a tight fit between the lower end of the hub wall and the'base of the neck. But there is another type of disconformity, namely where the hub can be forced all the way on without intimate contact between the upper end of the hub wall and the upper end of the tube neck, which disconformity was the primary cause of the production of defective units prior to this invention, In the case of the latter disconformity, illustrated with exaggeration in Fig. 2, the inside face I2 of the hub .is pressed against the rim of the dished blind end, causing the metal of the rim to be transported outwardly and into intimate contact with the upper end of the hub wall.

The assembled tube and needle is then used for the production of hypodermic units as de-' scribed inU. S. Patent 2,219,301; i. e., by inserting the stiff wire into the lumen of the needle (preferably a pointed and headed wire of non-rustable metal, having a slight bow to prevent its accidental dislodgement from the lumen of the needle), attaching the protective cover, filling the collapsible tube through its open end with the desired medicament or other substance, and hermetically-sealing the open end. The resultant hypodermic unit is, of course, used in the same manner as the unit described in that patent.

The invention may be variously otherwise em- 1. The method of producing a. hypodermicuhit comprising extruding a collapsible softmetal tube having an externally-tapered neck terminating in an integrally-extruded, readilypierceable externally dished blind end, posi-; tioning the hub of a hypodermic needle over the tube neck, the hub wall having a corresponding internal taper terminating in a substantiallyflat inside face at a depth less than the height of the tube neck, and forcing the hub upon the tube neck until the rim of the dished blind end is deformed by the inside face of the hub and brought into intimatev contact with the hub wall. 7

'2. A hypodermic unit comprising a collapsible soft-metal tube having an externally-tapered neck terminating in an integrally-extruded,

- readily-pierceable blind end, and a hypodermic bodied-401- example, as to shapes and proportionswithin the scope of the appended claims.

I claim:

needle having a hub frictionally and immovably secured to the outside of the tube neck, the lumen of the needle communicating with the outside of the blind end, the hub wall having a corresponding internal taperterminating in a substantially-fiat inside face at a depth less than the height of the tube neck, and the blind end of the tube neck having an integral annular outward extension in intimate contact with the inside face and Wall of the hub.

REFERENCES crrno The following references are of record in the file of this patent:

, UNITED STATES'VPATENTSI Number.

Name I 1 Date 937,029 Strong Oct. 12, 1909 1,373,669 Pittenger' Apr. 5., 1921 1,424,243 Fox Aug. 1, 1922 1,734,288 Davis .Nov, 5, 1929 1,742,044 r Meldrum Dem 31, 1929 1,992,605 Clifford Feb. 26, 1935 2,122,325 M Rumball June 2-8, 1938 2,219,301 Erhard Oct. 29, 1940 2,238,582 Dickinson Apr. 15, 1941 2,273,306 Woods Feb. 17, 1942 2,352,456 Temple :June 27, 1944 FOREIGN PATENTS Number Country Date 24,629 Great Britain May 22, 1911 

